Heat-exchange apparatus



' P. AUDIANNE. HEAT EXCHANGE A PPAHATUS. APPLICATION FILED JAN. 4, 1919.

Pa'iwanfied Nov. 9,1920.

2 SHEETS-SHEET 1 P. AUDlANNE. HEAT EXCHANGE APPARATUS. APPLICATION FILED 1AH.4. 1919.

Patanted Nov. 9, 1920..

2 SHEETS-SHEET 2.

.M: $5. a N

v/f uuug z w. .23: u 3% renew- RAUL AUTOIANHE, MARSEI'LLE, FRANCE.

Application filed. January 4, 1919. Serial No. 269,583.

us .iIl'RPFOVQDJEHbS in l-iea change i ppantus, ol which the following is a specilie 'on This invention has for its object a heat interchanger of high thermal efficiency specially applicable for the manufacture of sulfur trioxid or sulfuric acid. by the contact process. 1

The heat interchanger according to the present invention has a much greater etliciency than the interchangers hitherto ei ployod and it allows the gases to be satis- -factorily heated. without employing; fuel.

In the contact process for the manufacture of sulfuric acid it is necessary to warm the sulturous gases before introducing them into the Contact chambers and to cool the mixture leaving the contact chambers in order to be able toabsorb the sulfur trioxid formed.

As the oxidation of sulfur dioxid in the contact chambers liberates much heat, the temperature of the gas is considerably higher at the exit than at the inlet of the contact chamber. It is thus theoretically possible to utilize the heat of the exit gas to heat up the inletgas and thus to avoid the use of a source of external heat, at all terchanger to the requisite temperature for admission to the contact chamber.

The total avoidance of auxiliary, 2. e.-of

Epeeificution of Letters Patent.

aeration erranarns.

Patented hov. 9, 1920.

external heating ispossible in the first men tioned process because 01" the'special typeof contact chambers which do not require a gas inlet temperaturehigher than 220 C. In other processes however, for instance in the Grille-Schroeder process, the gas inlet temperature should reach about 300 C. Now the heat interchangers hitherto employed did not allowtheattainment of a temperature higher than 220 C. On the other hand the hot gases leaving the contact chamber enter the heat interchanger at a temperature which does not exceed 425 C. in any process owing to the conditions of the phenomenon of catalysis in this case. Hence, if the heated gases are to leave the heat interchanger at above 300 C., the apparatus must allow of much more complete exchange of heat than the interchangers hitherto employed.

The interchanger constructed according to the present invention exhibits this increased efliciency. i

The invention is illustrated by way of example in the accompanying drawings, in which Figure 1 is a vertical section of the heat interchanger,

Fin. 2 a horizontal section on the line 2-2 of Fig. l, i i V Fig. 3 a plan, 1

Fig. 4 detail of a throttling device C in elevation and FlQ. 5 is a in Fig. 4. i

The heatinterchanger is composed of a vertical s eel cylinder A containing a set of tubes B. i

The sulfur dioxid passes'upthrough the interior of the tubes and through the cones D, D, D, D, and out through the outlet plan view of the device shown F at the top of the apparatustrom whence it passes to the apparatus (not shown) where it 18 changed to sulfur trioxid, the

outlet 7 being adapted to be placed in com-' munication with the inlet of said sulfur trioxid apparatus. The gas then enters the chamber formed by the upper part of the their diameter are so cylinder A through the upper inlet Gr on the side of the apparatus, which inlet is adapted to be placed in communication with the outlet from the, sulfur trioXid apparatus. The gas is thus brought in contact with the exterior of the tubes Band passes through the chamber down around the tubes and out through the outlet ll. i The tubes are arranged close together that the total cross section available tor passage of the gas is equal inside and around the tubes. The volume of the gas to be treated being knowmthe diameter of the cylinder is such that the linear velocity of the gas is s'ufiicientlyhigh, for instance, greater than; three and. a half metersper second. 7

. Thelength of the tubes, theirnu'mberand chosen that the total surface availabletor exchange of heat, 210. the total. surtace o-t'the sides of the tubes, is five square ineters per ton of sultur'triexid passing through the apparatus in twenty four hoursif the are tube-heated to 220 C. or twenty five square meters per'ton per-twenty four hours if the gases are to be heated to 325 C. Finally, to assure that the s-ul'furousgas is evenly distributed within the tubes, these arepartially throttled at their lower end by devices C reducing the available cross sectional area of the inside of the tube. Thus tiese throttling devices C mayffor example consist oicast portions in the shape of a screw having three threads as shown in Fig. 4, or other similar arrangement may bemade which imparts a rotary or gyratory movement to the gas.

lo the same end the gases leaving theupper portion or t is tubes pass through a truncated dome D, Fig. h provided in'its interior with several concentric conical per tions D, D D spaced'apart in s chm nncr that gas will pass between the respe cones at'substantially the same rate in each. The "function of the conical portions Dfl), D and D is to assure an equal-distribrs tion ofthe-gas'throu'gh all ot the tubesli and therefore a more perfect utilization of the heatexchange surface. EJithout th se conical portions, the gas would have a'tendency'to passonly through the tubes atithe center ot'the cylinder rather than those at the periphery, but by the provision ofthe conical portions a uniform distribution of the gas throughthetubes is obtained.

The following example shows the main characteristics oftwo interchangers suitable staggered and so said cylinder eenununicatt for a production of ten tons of sulfur tri- =ox1d per twenty tour hour" a l A; v" 1 Diameter of cylinder 0.8 meters. 0. meters. Heat transferrmesuriaces ofiubes. 50 sq. meters 250 sq; meters. Temperature of sulfur die): at 40 1 -j:0 C.

' inlet t/i. 'lemperaturc of sulfur (iioxid at 220 C 320 (7.

exit t/o. Temperature of sulfur trioxid at 420 C 420 (3.

' inlet T/o. 7 Temperature of sulfur trioxid at 210 C 330 0.

exit T/i. a Thermal efiicicncyequal is 4 i i The apparatus in in spite of its srnal dimensions, is suitab e for contact plant in which the temperate atthe inletto the contactchamber should not be above 210 C. Plant fthe type it is much ore etllcientand when n plied to Grilloficnreeder process enables the use of tucl to be com- 'pletely avoided for heatin the when once normal conditions have been established. ln either case a bypass provided with a suitable valve al ows part of the cold gas to be diverted directto the contact chamber Without traversing the heat interchanger so as to controlthe temperature at the inlet to the contact chamber. 7

Having now particulars; described and ascertained the nature m"- my said. invention and in what manner the sameis to be performed l declare that what I is IM A heat interchan 'er comprising a cylindrical member divided into a plurality of compartments, a plurality oftubes interconnectin certain of said coznpaitmcuts said a n g cylinrtu'ical member being provided with an inlet at its lower end and an outlet atits upper end respectively communicating with said interconnecting compartments, and said cylinder being 0 provided intermediate its ends with an inlet outlet communicating with compartment that: is -out;ot communion with] said interconnected comgartments a plurality of hollow cone-shaped members in the upper part of atione" end with said tubes at theothcr end with a common-outlets In testimony whereof l have signed my nameto this specification. r

7 mm lama NNE.

Vi i nesses: f

Etienne .DUGASSON, JOHN TnAonY. 

